Multi-Layer Light Guiding Structure And Method For Using The Same

ABSTRACT

A key module with a multi-layer light guiding structure includes a plurality of keys, light guiding structure and a plurality of light blocks corresponding to the light guiding structure. The light guiding structure includes a plurality of light guiding plates. Each of the light guiding plate includes at least one light guiding strip corresponding to specific keys, which are staggered to each other or corresponding to each other. The light guiding strip is provided with a color layer. An electronic device using the key module individually or selectively lights light emitting elements for each layer of the light guiding plates. Therefore, different lights are emitted from the light guiding strips or a mixed light is produced from the light guiding strips to illuminate the keys. The keys have lights of different color to manifest symbols or alphabets on the keys.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a light guiding plate, moreparticularly, to a multi-layer light guiding structure

2. Description of Prior Art

Portable electronic device such as mobile phones and personal digitalassistants (PDA) are popular information appliances. In those portableelectronic devices, keys are often used for user input interface toinput data and select function of the electronic devices.

The key in the prior art electronic device generally comprises abacklight to provide illumination for user in dark environment.Therefore, user can correctly identify key. The conventional backlightcomprises a transparent light guide and a light emitting diode (LED) inthe electronic device. Light emitted from the LED is guided by the lightguide to distribute over bottom of each key. Therefore, symbols oralphabet can be clearly displayed on the key.

The LED in backlight application is generally of mono color, therefore,symbols or alphabet formed on top of the key are printed with differentcolor to provide colorful display effect. Alternatively, amultiple-color LED is used for a key when a specific color effect isdemanded for the key. The manufacture time and cost for above twoapproaches are burden for the manufacturer.

As the progress of technology, the electronic device is also providedwith more function for user. For example, mobile phone can be used forphoto, game and video playback. However, the backlight in the mobilephone illuminates symbols and alphabet on all keys. Therefore, usercannot identify the key for game control, photo shooting or videoplaying and the user is liable to have wrong operation. Moreover, themobile phone may be rotated during game control, photo shooting or videoplaying operation. The symbols and alphabet on the keys have differentorientation and the user cannot identify the key for game control, photoshooting or video playing, especially when the symbols and alphabet onthe keys are transparent.

SUMMARY OF THE INVENTION

The invention is to provide a multi-layer light guiding structure tocontrol the light emission from one key or multiple keys, whereby usercan clearly find the right keys.

Accordingly, the present invention provides a key module with amulti-layer light guiding structure, which includes a plurality of keys,light guiding structure and a plurality of light blocks corresponding tothe light guiding structure. The light guiding structure includes aplurality of light guiding plates. Each of the light guiding plateincludes at least one light guiding strip corresponding to specifickeys, which are staggered to each other or corresponding to each other.The light guiding strip is provided with a color layer. An electronicdevice using the key module individually or selectively lights lightemitting elements for each layer of the light guiding plates. Therefore,different lights are emitted from the light guiding strips or a mixedlight is produced from the light guiding strips to illuminate the keys.The keys have lights of different color to manifest symbols or alphabetson the keys.

BRIEF DESCRIPTION OF DRAWING

The features of the invention believed to be novel are set forth withparticularity in the appended claims. The invention itself however maybe best understood by reference to the following detailed description ofthe invention, which describes certain exemplary embodiments of theinvention, taken in conjunction with the accompanying drawings in which:

FIG. 1 shows the first preferred embodiment of the present invention.

FIG. 2 shows a top view of the first preferred embodiment of the presentinvention.

FIG. 3 shows the light refraction path of the first preferred embodimentof the present invention.

FIG. 4 shows the second preferred embodiment of the present invention.

FIG. 5 shows the key according a preferred embodiment of the presentinvention.

FIG. 6 shows the key in another orientation according a preferredembodiment of the present invention.

FIG. 7 shows the third preferred embodiment of the present invention.

FIG. 8 shows the fourth preferred embodiment of the present invention.

FIG. 9 shows the fifth preferred embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 shows the first preferred embodiment of the present invention.The present invention provides a multi-layer light guiding structure 10.The multi-layer light guiding structure 10 comprises a plurality oflight guiding plates 1, 1A and 1B, which comprises light guiding strips11, 11A and 11B corresponding to keys 41. Each of the light guidingstrips 11, 11A and 11B comprises pits 12, 12A, and 12B formed on thelight guiding plates 1, 1A and 1B, respectively. The pits 12, 12A, and12B change the optical paths of light to focus the light on specific key41 through refraction. Each of the light guiding strips 11, 11A and 11Bis coated with a specific color and the electronic device lights thelight-emitting elements 2, 2A and 2B individually or selectively,whereby light of different color is emitted from the light guidingstrips 11, 11A and 11B and illuminates the key module 4. The keys 41 onthe key module 4 have illumination of different color to display thealphabets and symbols thereon. In the shown embodiment, thelight-emitting elements 2, 2A and 2B are white LEDs.

The preferred embodiment is exemplified with three layers of lightguiding plates.

In the first light guiding plate 1, a light-emitting element 2 isarranged on one side of the light guiding plate 1 and a light block 3 isarranged atop the light guiding plate 1 and the light-emitting element2. The light block 3 is functioned to prevent interference of light toother light guiding plate or the key module. A light guiding strip 11 isarranged corresponding to the locations of keys 41 assigned for number“1”, “2”, and “3”. The light guiding strip 11 is coated with red colorto form red-color layer 5.

In the second light guiding plate 1A, a light-emitting element 2A isarranged on one side of the light guiding plate 1A and a light block 3Ais arranged atop the light guiding plate 1A and the light-emittingelement 2A. The light block 3A is functioned to prevent interference oflight to other light guiding plate or the key module. A light guidingstrip 1A is arranged corresponding to the locations of keys 41 assignedfor number “4”, “5”, and “6”. The light guiding strip 11A is coated withblue color to form blue-color layer 5A.

In the third light guiding plate 1B, a light-emitting element 2B isarranged on one side of the light guiding plate 1B and a light block 3Bis arranged atop the light guiding plate 1B and the light-emittingelement 2B. The light block 3B is functioned to prevent interference oflight to other light guiding plate or the key module. A light guidingstrip 11B is arranged corresponding to the locations of keys 41 assignedfor number “7”, “8”, and “9”. The light guiding strip 11B is coated withgreen color to form green-color layer 5B.

After the three light guiding plates 1, 1A and 1B are stacked, the lightguiding strips 11, 11A and 11B are staggered to each other andcorresponding to specific keys 41. Moreover, a light block 3C isprovided below the third light guiding plate 1B at the last layer andthe light-emitting element 2B. Moreover, when the light-emittingelements 2, 2A and 2B are of different color, for example, red LED,green LED and blue LED, the color layer 5, 5A and 5B can be eliminatedfor saving cost and reducing process complexity.

FIGS. 1 to 3 show the first preferred embodiment of the presentinvention. The electronic device (not shown) controls light source forthe multi-layer light guiding structure 10. When the light-emittingelement 2 is lighted, the light is guided by the light guiding plate 1and refracted by the light guiding strip 11 to the specific keys 41corresponding to numbers “1”, “2”, and “3”. The portion of keys 41corresponding to numbers “1”, “2”, and “3” are hollow, therefore, redcolor light can emit from the keys 41 to display numbers “1”, “2”, and“3”. The light block 3 prevents interference of light to the lightguiding plate 1A or the key module 4.

When the light-emitting element 2A is lighted, the light is guided bythe light guiding plate 1A and refracted by the light guiding strip 11Ato the keys 41 corresponding to numbers “4”, “5”, and “6”. The portionof keys 41 corresponding to numbers “4”, “5”, and “6” are hollow,therefore, blue color light can emit from the keys 41 to display numbers“4”, “5”, and “6”. The light block 3A prevents interference of light tothe light guiding plates 1 and 1B or the key module 4.

When the light-emitting element 2B is lighted, the light is guided bythe light guiding plate 1B and refracted by the light guiding strip 11Bto the keys 41 corresponding to numbers “7”, “8”, and “9”. The portionof keys 41 corresponding to numbers “7”, “8”, and “9” are hollow,therefore, green color light can emit from the keys 41 to displaynumbers “7”, “8”, and “9”. The light block 3B prevents interference oflight to the light guiding plate 1A.

When the light-emitting elements 2, 2A and 2B are lighted by theelectronic device, the keys 41 corresponding to numbers “1” to “9” havedifferent displaying colors.

FIG. 4 shows the second preferred embodiment of the present invention.As shown in this figure, each key 41 on the key module 4 comprisesalphabets (symbols) 411 and 412 with different orientations.

The first light guiding plate 1C comprises light guiding area 11Ccomposed of a plurality of pits. The area of the light guiding area 11Cis half or less than half of the key 41. The light guiding area 11C iscorresponding to the first number 411 of the key 41 and is coated with acolor layer 5. A light block 3 is arranged atop the light guiding plate1C and the light-emitting elements 2. In this figure, the light-emittingelement is white LED.

The second light guiding plate 1D comprises light guiding area 11Dcomposed of a plurality of pits. The area of the light guiding area 11Dis half or less than half of the key 41.

The light guiding area 11D is corresponding to the second number 412 ofthe key 41 and is coated with a color layer 5. A light block 3A isarranged atop the second light guiding plate 1D and the light-emittingelements 2A.

When the two light guiding plates 1C and 1D are stacked, the two lightguiding areas 11C and 11D are staggered to each other and correspondingto the two numbers 411 and 412 respectively.

Moreover, when the light-emitting elements 2 and 2A are of differentcolors, for example, red LED and green LED, the color layers 5 can beeliminated for saving cost and reducing process complexity.

With reference to FIGS. 4 to 6, when the light-emitting element 2 islighted by the electronic device (not shown), the light is guided by thefirst light guiding plate 1C and illuminates the first number 411 of thekey 41 by refraction of the light guiding area 11C. Therefore, light isemitted from the first number 411 while no light is emitted from thesecond number 412.

When user rotates the electronic device for playing game or watchingvideo clip, the light-emitting element 2A is lighted. The light isguided by the second light guiding plate 1D and illuminates the secondnumber 412 of the key 41 by refraction of the light guiding area 11D.Therefore, light is emitted from the second number 412 while no light isemitted from the first number 411. Therefore, user can focus hisconcentration on the right number (symbol) when operating the key 41 andis not influenced by another number of different orientation.

FIG. 7 shows the third preferred embodiment of the present invention,wherein light guiding strips 11 and 11A are provided for the first lightguiding plate 1 and the second light guiding plate 1A. The light guidingstrips 11 and 11A are coated with different colors. Therefore, lightscan be mixed when the light-emitting elements 2 and 2A are lighted atthe same time. For example, when the light-emitting element 2 emits redlight and the light-emitting element 2A emits blue light, the mixedcolor is purple.

Moreover, a light block 3 is provided between the first light guidingplate 1 and the second light guiding plate 1A, and between thelight-emitting element 2 and the light-emitting element 2A to preventinterference therebetween.

When the light-emitting elements 2 and 2A are implemented with LED ofdifferent colors such as red LED and blue LED, the color layers 5 can beeliminated for saving cost and reducing process complexity.

FIG. 8 shows the fourth preferred embodiment of the present invention.The multi-layer light guiding structure 10 is used for a key structure.The key structure comprises a first elastic layer 6 composed a pluralityof metal plates 61. When the key 91 is pressed, the metal plate 61 is incontact with circuit board of the electronic device (not shown). Themetal plate 61 also produces snap sound to provide tactile effect foruser.

A light guiding structure 10 is provided on the first elastic layer 6and comprises a plurality of light guiding plates. The light guidingstructure 10 and related light-emitting element and light block havebeen described with reference to FIGS. 1 and 7 and description thereofis omitted here for clarity.

A second elastic layer 7 is provided on the light guiding structure 10and comprises a rubber body 71 and a rigid plastic film 72 on thesurface of the rubber body 71. The rubber body 71 comprises a projection711 on bottom thereof and corresponding to the metal plates 61.

A binding layer 8 is arranged on the second elastic layer 7.

A key module 9 is arranged on the binding layer 8 and comprises aplurality of keys 91, each of keys 91 is corresponding to a projection711.

When the light-emitting elements are lighted individually orselectively, the light of different colors is guided by correspondinglight guiding plates. Therefore, lights of different colors pass throughthe surface of the keys 91.

When a key 91 is pressed by external force, the projection 711 of therubber body 71 is in contact with the light guiding structure 10 and thefirst elastic layer 6. Therefore, the metal plate 61 is in contact witha circuit board of the electronic device (not shown). The metal plate 61also produces snap sound to provide tactile effect for user.

FIG. 9 shows the fifth preferred embodiment of the present invention.The multi-layer light guiding structure 10 is used for a key structure.

The key structure comprises a first elastic layer 6 with a plurality ofapertures 62 and a metal plate 61 on opposite face of each aperture 62.When the key 91 is pressed by external force, the metal plates 61 is incontact with a circuit board of the electronic device (not shown). Themetal plate 61 also produces snap sound to provide tactile effect foruser.

A light guiding structure 10 is provided on the first elastic layer 6and comprises a plurality of light guiding plates. The light guidingstructure 10 and related light-emitting element and light block havebeen described with reference to FIGS. 1 and 7 and description thereofis omitted here for clarity. Each of the light guiding plates comprisesa through hole 101 thereon.

A key module 9 is arranged on the light guiding structure 10 andcomprises a plurality of keys 91, each of keys 91 comprises a secondelastic layer 92 made of transparent rubber material. A projection 93 isformed on the bottom of each second elastic layer 92 and passes throughthe through hole 101.

When the light-emitting elements are lighted individually orselectively, the lights of different colors are guided by correspondinglight guiding plates. Therefore, lights of different color pass throughthe surface of the keys 91.

When the key 91 is pressed by external force, the projection 93 of thesecond elastic layer 92 passes through the aperture 62 and the throughhole 101 and is then in contact with the metal plates 61. Therefore, themetal plate 61 is in contact with a circuit board of the electronicdevice (not shown). The metal plate 61 also produces snap sound toprovide tactile effect for user.

Although the present invention has been described with reference to thepreferred embodiment thereof, it will be understood that the inventionis not limited to the details thereof. Various substitutions andmodifications have suggested in the foregoing description, and otherwill occur to those of ordinary skill in the art. Therefore, all suchsubstitutions and modifications are intended to be embraced within thescope of the invention as defined in the appended claims.

1. A multi-layer light guiding structure arranged in an electronic device and corresponding to keys and a plurality of light-emitting elements of the electronic device, the multi-layer light guiding structure comprising: a plurality of light-guiding plates stacked together, a light-guiding strip formed on each of the light-guiding plates, the light-guiding strips being staggered to each other and corresponding to specific keys, wherein when each light-guiding plate guides light to the light-guiding strip, the light-guiding strip thereon is configured to refract light to corresponding key, whereby light of a specific color passes through a specific key.
 2. The multi-layer light guiding structure as in claim 1, wherein the light-guiding strip comprises a plurality of pits.
 3. The multi-layer light guiding structure as in claim 1, wherein the light-guiding strip comprises a color layer thereon.
 4. The multi-layer light guiding structure as in claim 1, further comprising a light block atop the light-guiding plate and the light-emitting element.
 5. A multi-layer light guiding structure arranged in an electronic device and corresponding to keys and a plurality of light-emitting elements of the electronic device, the multi-layer light guiding structure comprising: a light guiding structure comprising a plurality of light-guiding plates stacked together, a light-guiding strip formed on each of the light-guiding plates, the light-guiding strips being corresponding to each other, each of the light-guiding strips comprising a color layer; a light block arranged between two adjacent light-guiding plates and two light-emitting elements, wherein two light-guiding plates guide light to corresponding light-guiding strips, and the light-guiding strips refract light to a corresponding key, the light is filtered by the color layer, whereby light of a specific mixed color passes through the key.
 6. The multi-layer light guiding structure as in claim 5, wherein the light-guiding strip comprises a plurality of pits.
 7. The multi-layer light guiding structure as in claim 5, wherein the color layer of each of the light-guiding strips has different color.
 8. A multi-layer light guiding structure arranged in an electronic device and corresponding to keys and a plurality of light-emitting elements of the electronic device, the multi-layer light guiding structure comprising: a light guiding structure comprising a plurality of light-guiding plates stacked together, each of the light-guiding plates comprising a plurality of light-guiding areas, the light-guiding areas being staggered to each other and corresponding to alphabets and symbols of different orientations on the key; and a plurality of light blocks, each arranged between two adjacent light-guiding plates and two light-emitting elements, wherein when each light-guiding plate guides light to the light-guiding area, the light-guiding area thereon is configured to refract light to corresponding key, whereby light of a specific color passes through a specific key.
 9. The multi-layer light guiding structure as in claim 8, wherein the light-guiding strip comprises a plurality of pits.
 10. The multi-layer light guiding structure as in claim 8, wherein the light-guiding strip comprises a color layer thereon.
 11. A method for using a multi-layer light guiding structure, the multi-layer light guiding structure arranged in an electronic device and corresponding to keys and a plurality of light-emitting elements of the electronic device, the method comprising: a). providing a plurality of stacked light-guiding plates; b). providing a light-emitting element corresponding to each of the light-guiding plates; c). providing light-guiding strips on each light-guiding plate, which are staggered to each other and corresponding to specific keys of the key module; and d). individually or selectively lighting the light-emitting elements and guiding in the light by the light-guiding plate, where the light-guiding strips change optical path of the light to refract the light to the specific keys.
 12. The method as in claim 11, wherein the light-guiding strip comprises a plurality of pits.
 13. The method as in claim 11, wherein the light-guiding strip comprises a color layer.
 14. The method as in claim 11, wherein the multi-layer light guiding structure further comprises a light block between adjacent light-guiding plates and adjacent light-emitting elements.
 15. A key module having a multi-layer light guiding structure, the multi-layer light guiding structure arranged in an electronic device and corresponding to a plurality of light-emitting elements, the key module comprising: a first elastic layer comprising a plurality of metal plates thereon; a light-guiding structure arranged on the first elastic layer and comprising a plurality of light-guiding plates, each of the light-guiding plates comprising at least one light-guiding strip and the light-guiding strips of different layer of light-guiding plates being staggered to each other and corresponding to specific keys, where a light block is provided between adjacent light-guiding plates and adjacent light-emitting elements; a second elastic layer arranged on the light-guiding structure; and a key module arranged on the second elastic layer and comprising a plurality of keys, each key corresponding to a projection.
 16. The key module as in claim 15, wherein a binding layer is provided between the second elastic layer and the key module.
 17. The key module as in claim 15, wherein the second elastic layer comprises a rubber body and a rigid plastic film on surface of the rubber body, the rubber body comprising a projection on bottom thereof.
 18. The key module as in claim 15, wherein the light-guiding strip comprises a plurality of pits.
 19. The key module as in claim 15, wherein the light-guiding strip comprises a color layer.
 20. The key module as in claim 15, wherein the light-guiding structure comprises a plurality of light-guiding plates, each of the light-guiding plates comprises at least one light-guiding strip and the light-guiding strips are corresponding to respective keys, a color layer is provided for each light-guiding strip and a light block is arranged between two adjacent light-guiding plates and two light-emitting elements.
 21. The key module as in claim 15, wherein the wherein the light-guiding structure comprises a plurality of light-guiding plates, each of the light-guiding plates comprises a plurality of light-guiding areas and the light-guiding areas are staggered to each other and corresponding to respective keys, a color layer is provided for each light-guiding area and a light block arranged between two adjacent light-guiding plates and two light-emitting elements.
 22. A key module having a multi-layer light guiding structure, the multi-layer light guiding structure arranged in an electronic device and corresponding to a plurality of light-emitting elements, the key module comprising: a first elastic layer comprising a plurality of apertures and each aperture containing a metal plates therein; a light-guiding structure arranged on the first elastic layer and comprising a plurality of light-guiding plates stacked to each other, each of the light-guiding plates comprising at least one light-guiding strip and a plurality of through holes, the light-guiding strips of different layer of light-guiding plates being staggered to each other and corresponding to specific keys, where a light block is provided between adjacent light-guiding plates and adjacent light-emitting elements; and a key module arranged on the light-guiding structure and comprising a plurality of keys, the key comprising a second elastic layer and the second elastic layer comprising a projection passing through the through hole of each layer of light-guiding plate.
 23. The key module as in claim 22, wherein the light-guiding strip comprises a plurality of pits.
 24. The key module as in claim 22, wherein the light-guiding strip comprises a color layer.
 25. The key module as in claim 22, wherein the light-guiding structure comprises a plurality of light-guiding plates, each of the light-guiding plates comprises at least one light-guiding strip and the light-guiding strips are corresponding to respective keys, a color layer is provided for each light-guiding strip and a light block is arranged between two adjacent light-guiding plates and two light-emitting elements.
 26. The key module as in claim 22, wherein the wherein the light-guiding structure comprises a plurality of light-guiding plates, each of the light-guiding plates comprises a plurality of light-guiding areas and the light-guiding areas are staggered to each other and corresponding to respective keys, a color layer is provided for each light-guiding area and a light block arranged between two adjacent light-guiding plates and two light-emitting elements. 